1. Field of the Invention
The present invention relates to a device for displacing a tenser in a two-for-one twister in which a tension applying device is installed within a center hole of a yarn supply package.
2. Description of the Related Art
A two-for-one twister houses therein a tension applying device. That is, in a tension device installed within a center hole of a yarn supply package, a capsule type or a spherical tenser is provided in part of a yarn passing hole, and tension is applied to a yarn while nipping the yarn under constant pressure between the tenser and the tenser supporting member.
In case of such a tension device, in threading operation, it is necessary to displace the tenser from a yarn passage to provide freedom without any abstacle in the yarn passage. Where threading is carried out by a guide means such as flexible nylon, or where threading is carried out by air stream, it is necessary to displace the tenser to a position not to cutoff an air stream passage.
Various tenser displacing devices have been proposed. However, some of these devices are inconvenient in positiveness of displacement of the tenser. That is, a tenser is displaced by compressed air; a push rod having a tapered end is inserted into a yarn guide hole to directly and forcibly displace the tenser; or a pin is projected from a cylindrical side to forcibly move the pin in a lateral direction. However, these proposals have disadvantages such that in case of using the compressed air, there involves inaccuracy in operation due to variation in air pressure and air leakage; in case of inserting the displacing push rod, the operation is cumbersome; and in case of pushing a pin from the side, the directivity of operation need be determined.